Intra spinal fixation rod



F 1968 c. H. FRAZER 3,367,326

INTRA SPINAL FIXATION ROD Filed June 15, 1965 INVENTOR.

CAL V/N H. FRAZ/E/i ZFJG. J). BY

,4 1- T0 ENE vs.

Unite States Pate 3,3573% Patented Feb. 6, 1968 3,367,326 INTRA SPINALFIXATIQN ROD Calvin H. Frazier, 650 Rambler Road, Merced, Calif. 95340Filed June 15, 1965, Ser. No. 464,139 8 Claims. (Cl. 12892) ABSTRACT OFTHE DESCLQSURE An improved tapered intra-medullary spinal fixation rodhaving a drill tip at the tapered end and the method of using the rod tosupport a human spine by drilling the rod through successive vertebrae.

The present invention relates to bone surgery, and pertains moreparticularly to a means for and method of positioning and supporting aspine.

In the case of a malformed spine, or one weakened by injury or disease,it frequently would be of inestimable value if the spine could bebrought toward its normal or correct shape and maintained in thatposition. It is common practice in some bone breaks, for example, theneck of the femur, to insert a metal pin lengthwise through the twoparts of the bone to secure them in properly set position. Priorattempts have been made to stabilize the spine by metal pins and platesembedded alongside the spine, and by various orthopedic harnessesstrapped onto the body, but to date no known prior means or method hasprovided satisfactory, and if necessary permanent, positioning andstabilization for a malformed, weak or injured spine.

The present invention is directed toward the positioning and stabilizingof a human spine.

A further object of the invention is to provide an improvedintra-medullary spinal fixation rod for inserting through the centrum ofeach of a plurality of adjacent vertabrael processes of a human spine.

A further object of the invention is to provide an elongated, taperedrod with a drill tip thereon, the rod and drill tip being of a metalwhich will be tolerated by, and stable within, a human body, the rod anddrill tip being formed for drilling into and through a plurality ofsuccessive spinal vertabrae to support, stabilize and the spine in whichsuch vertebrae are located.

A further object of the invention is to provide an improved method forpositioning and stabilizing a plurality of adjacent spinal vertebrae byinserting through the centrum of the vertebral process of each of suchvertebrae a metal rod, and then, if the rod is to remain therein,severing the rod at a point below the spine which will be Within thebody upon healing.

A further object of the invention is to provide an improved method forpositioning and stabilizing a human spine which comprises inserting astabilizing rod through a plurality of successive vertebrae of suchspine while observing by radiograph the forward tip of the rod as itproceeds along its course.

The foregoing objects and advantages of the invention will be apparentfrom the following description and the accompanying drawings, wherein:

FIG. 1 is a somewhat diagrammatic, perspective view showing theinsertion of an intra-medullary spinal fixation rod in accordance withthe present invention.

FIG. 2 is an enlarged, side elevational view of a preferred form ofspinal fixation rod embodying the invention.

FIG. 3 is a similar view in reduced scale of a curved spinal fixationrod which can be employed where a slight curvature is desired.

FIG. 4 is a somewhat diagrammatic, side elevational view of a spinalcolumn with the skull and a portion of the rib cage attached, the brokenline showing the location of a spinal fixation rod inserted inaccordance with the invention.

FIG. 5 is a plan view of a thoracic vertebra with the target location ofthe rod in the centrum indicated by the dotted line circle.

Briefly, in the illustrative form of the present invention, anintramedullary spinal fixation rod or pin 10 preferably is tapered asshown in FIG. 2 with the leading end thereof in the form of a drill tip11. The rear or driving end of the rod 10 is adapted to be chucked in asuitable drill, such as that A shown in FIG. 1.

The rod 10 preferably is inserted in the peri-anal region or through thecolon and thence onto the lower end of the spine 12 (FIG. 4) by drillingthrough the sacrum. The rent in the colon can be repaired after the rodhas been driven through it. The rod 10 is guided to course upwardlythrough the centrum of each successive vertebra until a desiredpenetration has been achieved. The lower end of the rod 12 may then besevered, and the portion which has penetrated the spine remains inposition therein. During the insertion of the rod 10, the progress ofthe leading end thereof preferably is followed by radiographobservations.

Referring to the drawings in greater detail, a presently preferredspinal fixation rod 10 (FIG. 2) is of suitable metal, which isrelatively inert, and which will be well tolerated within the body, forexample, a metal of the type used in the making of an intramedullary rodor nail of the type used for pinning broken bones, such as a bone of theleg or arm. The rod 10 is gradually tapered from the rear or driving end13 toward the forward or leading tip end 11, since the vertebral bodies12a, forwardly of the spinal cord 14 (FIG. 5), through which the rod 10is inserted are of smaller size toward the upper end of the spine thanthey are toward the lower end thereof.

The rear or driving end 13 of the rod 10 is adapted to be chucked in thechuck 15 of a suitable drill, such as the usual half-inch electric drillA (FIG. 1) having a conventional AC-DC motor and employing a well knowntype of electronic speed control mechanism (not shown) employing asilicon rectifier to change AC line current to half-wave DC and apotentiometer, and employing a feed-back circuit to provide adequatetorque at low speeds.

The forward tip portion 11 of the tapered rod 10 is in the form of adrill, the specific type of drill not being a feature of the presentinvention provided it is suitable for drilling through bone. Most of thepath of the drill, as is obvious from the dotted line 17 indicating suchpath in FIG. 4, is in comparatively soft, inner bone structure andcartilage, although at the zone of entry into the sacrum it is, ofcourse, harder.

It is not always necessary that the rod 10 be stiff, and it may bedesirable in some instances that it be quite bendable either in part orthroughout its entire length. It is obvious from FIG. 4 that in order toinsert the rod 10 into the spinal processes of the upper thoracicregion, and thence, if necessary, on into those of the cervical region,a bending of the rod 10 will be essential. Such bending can beaccomplished, for example, by empioying a slightly bendable rod with aslightly offset tip thereon and drilling to the maximum distance whereinthe spine can be manipulated into a sufiiciently straight position topermit such drilling. From this point on the rod can be driven, the rodbeing turned to direct the offset tip toward either the front or back asrequired, by rotatively moving the rod through an angle of Suchpositioning of the offset tip will cause a deflection of the tip along adesired path, the rod being sufliciently flexible to permit it to followsuch gradually deflected path. Another means for inserting the rod alonga curved path is to employ a flexible rod with a drill tip on theleading end thereof oflset to one side slightly so as to cause the drilltip to drift in the direction in which the tip is offset when the rod isoscillated, and to follow a straight course when the rod is rotated.

Some changes in the alignment of successive vertebrae, at least those ofthe lumbar region is usually possible by manipulation of the body of thesubject as the drill advances from one vertebra to the next, thereby tomaintain the drill tip on its desired course. The requirement for a moreor less flexible rod, and a curving or drifting course for the tip 11becomes necessary only in cases of an uncorrectable curvature, or foradvancement of the rod into the upper portions of the spine, where thepresence of the rib cage restricts such manipulation.

A presently preferred method for inserting the rod 10 into a spine 12 isas follows:

The drill tip 11 is introduced in the peri-anal region, or through thecolon. The progress of the tip 11 of the rod 10 is observed at requiredintervals throughout the insertion procedure by radiograph observation,preferably employing two X-ray machines 20 and 21 with their ray axesdirected toward a desired point along the spine, and offset from eachother through a selected transverse angle, preferably of approximately90 as shown in FIG. 1.

The rod 10 is directed so that it passes through the sacrum and entersthe centrum of the spinal process of the lowermost lumbar vertebra.Thence it is directed along a course through the centrum of eachsuccessive vertebra until a desired penetration has been attained, forexample, when the zone of the spine which it is desired to straighten orstabilize has the rod inserted therein. The rod 10 is then released fromthe drill chuck 15, and is cut off as by means of a bolt cutter (notshown) at a desired point, preferably a point which will be within thebody after healing if the rod is to remain in place permanently. If therod is to be removed after a spinal healing process has occurred, therod is allowed to project so that it can be manipulated as required forits withdrawal.

If it is necessary to advance to rod 10 to a point in the spine whichcannot be reached with a straight rod, a rod of suitable flexibility isemployed, and is guided in its course from one vertebra to the next asrequired and as set forth previously herein. Also, in some cases, itmight be desirable to insert a pro-formed rod such as that 10a shown inFIG. 3.

The invention provides a means and method for straightening andstrengthening malformed, injured, diseased and weakened spines wherebyit is possible to restore to almost normal condition and use, manypersons who at present are suffering from such spinal conditions.

While I have illustrated and described a preferred embodiment of thepresent invention, it will be understood, however, that various changesand modifications may be made in the details thereof without departingfrom the scope of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire toprotect by Letters Patent is defined in the following claims:

1. The method of supporting a malformed, injured or diseased spine whichcomprises introducing into the analperi-anal region of a person whosespine is to be supported the tip of an elongated rod of material whichwill be tolerated within such spine, and thence inserting the rodthrough the centrum of the vertebral process of each of a selectedplurality of successive vertebrae of such spine.

2. The method of supporting a malformed, injured or diseased spine whichcomprises introducing into the analperi-anal region of one Whose spineis to be supported the rotating drill tip of an elongated rod of smalldiameter, and of a material which will be tolerated within such spine,and thence inserting the rod in such spine by drilling with the drilltip of the rod through the centrum of the vertebral process of each of aselected plurality of successive vertebrae of such spine.

3. The method of supporting a malformed, injured or diseased spine whichcomprises introducing a rotary drill into the anal-peri-anal region ofone whose spine is to be supported, of drilling into and through thecentrum of the vertebral process of each of a selected plurality ofsuccessive vertebrae of such spine, and of inserting into the holes thusdrilled a small diameter rod of a material will be tolerated within suchspine.

4. The method set forth in claim 3 wherein after insertion of the rod inthe holes, the rod is severed below its point of entry into thelowermost vertebra at which it enters such spine.

5. An intrarnedullary spinal fixation rod comprising an elongated rod ofround cross sectional shape and of a material which will be toleratedwith a human spine, means for mounting one end of the rod in powerdriven chuck means for controlled rotation of the rod about its axis,the other end of the rod being in the form of a drill suitable fordrilling in bone, the rod being tapered from said one end toward saiddrill end, and of a length for introduction at a selected zone of theanal and peri-anal region and insertion by drilling thence through thesacrum and the centrum of the vertebral process of each of a selectedplurality of successive vertebrae of a human spine, one or more of whichvertebrae is to be positioned and supported by the rod.

6. An intramedullary spinal fixation rod comprising an elongated rod ofround cross sectional shape and of a material which will be toleratedwith a human spine, power driven means operatively engaging the rod forcontrolled rotative movement of the rod about its axis, the leading endof the rod being in the form of a drill suitable for drilling in bone,the rod being tapered toward said drill end, and of a length forintroduction at a selected zone of the anal and peri-anal region andinsertion by drilling thence into and through the centrum of thevertebral process of each of a selected plurality of successivevertebrae of a human spine, one or more of which vertebrae is to bepositioned and supported by the rod.

7. An arrangement according to claim 5 wherein a selected portion of therod is sufiiciently flexible to follow a curved course in a selectedportion of its path into and through the selected vertebrae.

8. An arrangement according to claim 5 .wherein the rod is formed tofollow a curved course in its path into and through selected vertebrae.

References Cited UNITED STATES PATENTS 2,702,031 2/1955 Wenger 128-922,774,350 12/1956 Cleveland 128-92 2,952,254 9/1960 Keating 128923,118,444 1/1964 Serrato 128-92 3,242,922 3/1966 Thomas l28-92 RICHARDA. GAUDET, Primary Examiner.

I. W. HINEY, Assistant Examiner,

